An increased research on electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV) deals with their flexible use in electric power grids. Several research projects on smart grids and electric mobility are now looking into realistic models representing the behavior of an EV during charging, including nonlinearities. In this work, modeling, simulation and testing of the demand profile of a battery-EV are conducted. Realistic work conditions for a lithium-ion EV battery and battery charger are considered as the base for the modeling. Simulation results show that EV charging generates different demand profiles into the grid, depending on the applied charging option. Moreover, a linear region for the control of EV chargers is identified in the range of 20-90% state-of-charge (SOC). Experiments validate the proposed model.